class SearchNum:
    """
    Given an array of integers nums which is sorted in ascending order,
    and an integer target, write a function to search target in nums.
    If target exists, then return its index. Otherwise, return -1.

Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4
Example 2:
Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1
    """

    def search(self, nums: list, target: int):
        left, right = 0, len(nums)
        while left < right:
            mid = (left + right) // 2
            if nums[mid] < target:
                left = mid + 1
            elif nums[mid] > target:
                right = mid
            else:
                return mid
        return -1


if __name__ == '__main__':
    nums = [-1, 0, 3, 5, 9, 12]
    target = 9
    nums1 = [-1, 0, 3, 5, 9, 12]
    target1 = 2
    s = SearchNum()
    res = s.search(nums, target)
    res1 = s.search(nums1, target1)
    print("示例1的结果：", res)
    print("示例2的结果：", res1)
